Vulnerabilities > CVE-2017-2536 - Improper Restriction of Operations within the Bounds of a Memory Buffer vulnerability in Apple Safari
Attack vector
NETWORK Attack complexity
LOW Privileges required
NONE Confidentiality impact
HIGH Integrity impact
HIGH Availability impact
HIGH Summary
An issue was discovered in certain Apple products. iOS before 10.3.2 is affected. Safari before 10.1.1 is affected. tvOS before 10.2.1 is affected. The issue involves the "WebKit" component. It allows remote attackers to execute arbitrary code or cause a denial of service (memory corruption and application crash) via a crafted web site.
Vulnerable Configurations
Common Weakness Enumeration (CWE)
Common Attack Pattern Enumeration and Classification (CAPEC)
- Buffer Overflow via Environment Variables This attack pattern involves causing a buffer overflow through manipulation of environment variables. Once the attacker finds that they can modify an environment variable, they may try to overflow associated buffers. This attack leverages implicit trust often placed in environment variables.
- Overflow Buffers Buffer Overflow attacks target improper or missing bounds checking on buffer operations, typically triggered by input injected by an attacker. As a consequence, an attacker is able to write past the boundaries of allocated buffer regions in memory, causing a program crash or potentially redirection of execution as per the attackers' choice.
- Client-side Injection-induced Buffer Overflow This type of attack exploits a buffer overflow vulnerability in targeted client software through injection of malicious content from a custom-built hostile service.
- Filter Failure through Buffer Overflow In this attack, the idea is to cause an active filter to fail by causing an oversized transaction. An attacker may try to feed overly long input strings to the program in an attempt to overwhelm the filter (by causing a buffer overflow) and hoping that the filter does not fail securely (i.e. the user input is let into the system unfiltered).
- MIME Conversion An attacker exploits a weakness in the MIME conversion routine to cause a buffer overflow and gain control over the mail server machine. The MIME system is designed to allow various different information formats to be interpreted and sent via e-mail. Attack points exist when data are converted to MIME compatible format and back.
Exploit-Db
| file | exploits/macos/remote/42125.txt |
| id | EDB-ID:42125 |
| last seen | 2018-11-30 |
| modified | 2017-06-06 |
| platform | macos |
| port | |
| published | 2017-06-06 |
| reporter | Exploit-DB |
| source | https://www.exploit-db.com/download/42125 |
| title | Apple Safari 10.1 - Spread Operator Integer Overflow Remote Code Execution |
| type | remote |
Nessus
NASL family MacOS X Local Security Checks NASL id MACOSX_SAFARI10_1_1.NASL description The version of Apple Safari installed on the remote macOS or Mac OS X host is prior to 10.1.1. It is, therefore, affected by multiple vulnerabilities : - An unspecified flaw exists in the history menu functionality. An unauthenticated, remote attacker can exploit this to cause a denial of service condition. (CVE-2017-2495) - Multiple memory corruption issues exist in the WebKit component due to improper validation of user-supplied input. An unauthenticated, remote attacker can exploit these issues, by convincing a user to visit a specially crafted website, to execute arbitrary code. (CVE-2017-2496, CVE-2017-2505, CVE-2017-2506, CVE-2017-2514, CVE-2017-2515, CVE-2017-2521, CVE-2017-2525, CVE-2017-2526, CVE-2017-2530, CVE-2017-2531, CVE-2017-2538, CVE-2017-2539, CVE-2017-2544, CVE-2017-2547, CVE-2017-6980, CVE-2017-6984) - A memory corruption issue exists in the WebKit Web Inspector component that allows an unauthenticated, remote attacker to execute arbitrary code. (CVE-2017-2499) - An address bar spoofing vulnerability exists due to improper state management. An unauthenticated, remote attacker can exploit this to spoof the address in the address bar. (CVE-2017-2500, CVE-2017-2511) - Multiple universal cross-site scripting (XSS) vulnerabilities exist in WebKit due to improper handling of WebKit Editor commands, container nodes, pageshow events, frame loading, and cached frames. An unauthenticated, remote attacker can exploit this, via a specially crafted web page, to execute arbitrary script code in a user last seen 2020-06-01 modified 2020-06-02 plugin id 100355 published 2017-05-23 reporter This script is Copyright (C) 2017-2019 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/100355 title macOS : Apple Safari < 10.1.1 Multiple Vulnerabilities code # # (C) Tenable Network Security, Inc. # include("compat.inc"); if (description) { script_id(100355); script_version("1.5"); script_cvs_date("Date: 2019/11/13"); script_cve_id( "CVE-2017-2495", "CVE-2017-2496", "CVE-2017-2499", "CVE-2017-2500", "CVE-2017-2504", "CVE-2017-2505", "CVE-2017-2506", "CVE-2017-2508", "CVE-2017-2510", "CVE-2017-2511", "CVE-2017-2514", "CVE-2017-2515", "CVE-2017-2521", "CVE-2017-2525", "CVE-2017-2526", "CVE-2017-2528", "CVE-2017-2530", "CVE-2017-2531", "CVE-2017-2536", "CVE-2017-2538", "CVE-2017-2539", "CVE-2017-2544", "CVE-2017-2547", "CVE-2017-2549", "CVE-2017-6980", "CVE-2017-6984" ); script_bugtraq_id( 98454, 98455, 98456, 98470, 98473, 98474 ); script_xref(name:"APPLE-SA", value:"APPLE-SA-2017-05-15-7"); script_name(english:"macOS : Apple Safari < 10.1.1 Multiple Vulnerabilities"); script_summary(english:"Checks the Safari version."); script_set_attribute(attribute:"synopsis", value: "A web browser installed on the remote macOS or Mac OS X host is affected by multiple vulnerabilities."); script_set_attribute(attribute:"description", value: "The version of Apple Safari installed on the remote macOS or Mac OS X host is prior to 10.1.1. It is, therefore, affected by multiple vulnerabilities : - An unspecified flaw exists in the history menu functionality. An unauthenticated, remote attacker can exploit this to cause a denial of service condition. (CVE-2017-2495) - Multiple memory corruption issues exist in the WebKit component due to improper validation of user-supplied input. An unauthenticated, remote attacker can exploit these issues, by convincing a user to visit a specially crafted website, to execute arbitrary code. (CVE-2017-2496, CVE-2017-2505, CVE-2017-2506, CVE-2017-2514, CVE-2017-2515, CVE-2017-2521, CVE-2017-2525, CVE-2017-2526, CVE-2017-2530, CVE-2017-2531, CVE-2017-2538, CVE-2017-2539, CVE-2017-2544, CVE-2017-2547, CVE-2017-6980, CVE-2017-6984) - A memory corruption issue exists in the WebKit Web Inspector component that allows an unauthenticated, remote attacker to execute arbitrary code. (CVE-2017-2499) - An address bar spoofing vulnerability exists due to improper state management. An unauthenticated, remote attacker can exploit this to spoof the address in the address bar. (CVE-2017-2500, CVE-2017-2511) - Multiple universal cross-site scripting (XSS) vulnerabilities exist in WebKit due to improper handling of WebKit Editor commands, container nodes, pageshow events, frame loading, and cached frames. An unauthenticated, remote attacker can exploit this, via a specially crafted web page, to execute arbitrary script code in a user's browser session. (CVE-2017-2504, CVE-2017-2508, CVE-2017-2510, CVE-2017-2528, CVE-2017-2549) - Multiple unspecified flaws exist in WebKit that allow an unauthenticated, remote attacker to corrupt memory and execute arbitrary code by using specially crafted web content. (CVE-2017-2536)"); script_set_attribute(attribute:"see_also", value:"https://support.apple.com/en-us/HT207804"); # https://lists.apple.com/archives/security-announce/2017/May/msg00003.html script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?7a320df7"); script_set_attribute(attribute:"solution", value: "Upgrade to Apple Safari version 10.1.1 or later."); script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:N/C:P/I:P/A:P"); script_set_cvss_temporal_vector("CVSS2#E:POC/RL:OF/RC:C"); script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H"); script_set_cvss3_temporal_vector("CVSS:3.0/E:P/RL:O/RC:C"); script_set_attribute(attribute:"cvss_score_source", value:"CVE-2017-6984"); script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available"); script_set_attribute(attribute:"exploit_available", value:"true"); script_set_attribute(attribute:"vuln_publication_date", value:"2017/05/15"); script_set_attribute(attribute:"patch_publication_date", value:"2017/05/15"); script_set_attribute(attribute:"plugin_publication_date", value:"2017/05/23"); script_set_attribute(attribute:"plugin_type", value:"local"); script_set_attribute(attribute:"cpe", value:"cpe:/a:apple:safari"); script_end_attributes(); script_category(ACT_GATHER_INFO); script_family(english:"MacOS X Local Security Checks"); script_copyright(english:"This script is Copyright (C) 2017-2019 and is owned by Tenable, Inc. or an Affiliate thereof."); script_dependencies("macosx_Safari31.nasl"); script_require_keys("Host/local_checks_enabled", "Host/MacOSX/Version", "MacOSX/Safari/Installed"); exit(0); } include("audit.inc"); include("global_settings.inc"); include("misc_func.inc"); if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED); os = get_kb_item("Host/MacOSX/Version"); if (!os) audit(AUDIT_OS_NOT, "Mac OS X or macOS"); if (!ereg(pattern:"Mac OS X 10\.(10|11|12)([^0-9]|$)", string:os)) audit(AUDIT_OS_NOT, "Mac OS X Yosemite 10.10 / Mac OS X El Capitan 10.11 / macOS Sierra 10.12"); installed = get_kb_item_or_exit("MacOSX/Safari/Installed", exit_code:0); path = get_kb_item_or_exit("MacOSX/Safari/Path", exit_code:1); version = get_kb_item_or_exit("MacOSX/Safari/Version", exit_code:1); fixed_version = "10.1.1"; if (ver_compare(ver:version, fix:fixed_version, strict:FALSE) == -1) { report = report_items_str( report_items:make_array( "Path", path, "Installed version", version, "Fixed version", fixed_version ), ordered_fields:make_list("Path", "Installed version", "Fixed version") ); security_report_v4(port:0, severity:SECURITY_WARNING, extra:report, xss:true); } else audit(AUDIT_INST_PATH_NOT_VULN, "Safari", version, path);NASL family Misc. NASL id APPLETV_10_2_1.NASL description According to its banner, the version of Apple TV on the remote device is prior to 10.2.1. It is, therefore, affected by multiple vulnerabilities : - A memory corruption issue exists in the WebKit Web Inspector component that allows an unauthenticated, remote attacker to execute arbitrary code. (CVE-2017-2499) - An unspecified race condition exists in the Kernel component that allows a local attacker to execute arbitrary code with kernel-level privileges. (CVE-2017-2501) - An information disclosure vulnerability exists in the CoreAudio component due to improper sanitization of certain input. A local attacker can exploit this to read the contents of restricted memory. (CVE-2017-2502) - A universal cross-site scripting (XSS) vulnerability exists in WebKit due to a logic flaw when handling WebKit Editor commands. An unauthenticated, remote attacker can exploit this, via a specially crafted web page, to execute arbitrary script code in a user last seen 2020-06-01 modified 2020-06-02 plugin id 100256 published 2017-05-17 reporter This script is Copyright (C) 2017-2019 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/100256 title Apple TV < 10.2.1 Multiple Vulnerabilities code # # (C) Tenable Network Security, Inc. # include("compat.inc"); if (description) { script_id(100256); script_version("1.9"); script_cvs_date("Date: 2019/11/13"); script_cve_id( "CVE-2017-2499", "CVE-2017-2501", "CVE-2017-2502", "CVE-2017-2504", "CVE-2017-2505", "CVE-2017-2507", "CVE-2017-2513", "CVE-2017-2515", "CVE-2017-2518", "CVE-2017-2519", "CVE-2017-2520", "CVE-2017-2521", "CVE-2017-2524", "CVE-2017-2525", "CVE-2017-2530", "CVE-2017-2531", "CVE-2017-2536", "CVE-2017-2549", "CVE-2017-6979", "CVE-2017-6980", "CVE-2017-6984", "CVE-2017-6987", "CVE-2017-6989", "CVE-2017-7003", "CVE-2017-7005" ); script_bugtraq_id( 98454, 98455, 98456, 98457, 98468, 98473 ); script_name(english:"Apple TV < 10.2.1 Multiple Vulnerabilities"); script_summary(english:"Checks the build number."); script_set_attribute(attribute:"synopsis", value: "The remote Apple TV device is affected by multiple vulnerabilities."); script_set_attribute(attribute:"description", value: "According to its banner, the version of Apple TV on the remote device is prior to 10.2.1. It is, therefore, affected by multiple vulnerabilities : - A memory corruption issue exists in the WebKit Web Inspector component that allows an unauthenticated, remote attacker to execute arbitrary code. (CVE-2017-2499) - An unspecified race condition exists in the Kernel component that allows a local attacker to execute arbitrary code with kernel-level privileges. (CVE-2017-2501) - An information disclosure vulnerability exists in the CoreAudio component due to improper sanitization of certain input. A local attacker can exploit this to read the contents of restricted memory. (CVE-2017-2502) - A universal cross-site scripting (XSS) vulnerability exists in WebKit due to a logic flaw when handling WebKit Editor commands. An unauthenticated, remote attacker can exploit this, via a specially crafted web page, to execute arbitrary script code in a user's browser session. (CVE-2017-2504) - Multiple memory corruption issues exist in WebKit due to improper validation of certain input. An unauthenticated, remote attacker can exploit these to execute arbitrary code. (CVE-2017-2505, CVE-2017-2515, CVE-2017-2521, CVE-2017-2530, CVE-2017-2531, CVE-2017-6980, CVE-2017-6984) - Multiple information disclosure vulnerabilities exist in the Kernel component due to improper sanitization of certain input. A local attacker can exploit these to read the contents of restricted memory. (CVE-2017-2507, CVE-2017-6987) - A use-after-free error exists in the SQLite component when handling SQL queries. An unauthenticated, remote attacker can exploit this to deference already freed memory, resulting in the execution of arbitrary code. (CVE-2017-2513) - Multiple buffer overflow conditions exist in the SQLite component due to the improper validation of certain input. An unauthenticated, remote attacker can exploit these, via a specially crafted SQL query, to execute arbitrary code. (CVE-2017-2518, CVE-2017-2520) - A memory corruption issue exists in the SQLite component when handling SQL queries. An unauthenticated, remote attacker can exploit this, via a specially crafted query, to execute arbitrary code. (CVE-2017-2519) - An unspecified memory corruption issue exists in the TextInput component when parsing specially crafted data. An unauthenticated, remote attacker can exploit this to execute arbitrary code. (CVE-2017-2524) - A use-after-free error exists in WebKit when handling RenderLayer objects. An unauthenticated, remote attacker can exploit this, via a specially crafted web page, to deference already freed memory, resulting in the execution of arbitrary code. (CVE-2017-2525) - Multiple unspecified flaws exist in WebKit that allow an unauthenticated, remote attacker to corrupt memory and execute arbitrary code by using specially crafted web content. (CVE-2017-2536) - A universal cross-site scripting (XSS) vulnerability exists in WebKit due to a logic error when handling frame loading. An unauthenticated, remote attacker can exploit this, via a specially crafted web page, to execute arbitrary code in a user's browser session. (CVE-2017-2549) - An unspecified flaw exists in the IOSurface component that allows a local attacker to corrupt memory and execute arbitrary code with kernel-level privileges. (CVE-2017-6979) - An unspecified flaw exists in the AVEVideoEncoder component that allows a local attacker, via a specially crafted application, to corrupt memory and execute arbitrary code with kernel-level privileges. (CVE-2017-6989) - A denial of service vulnerability exists in the CoreText component due to improper validation of user-supplied input. An unauthenticated, remote attacker can exploit this, via a specially crafted file, to crash an application. (CVE-2017-7003) - A memory corruption issue exists in the JavaScriptCore component due to improper validation of user-supplied input. An unauthenticated, remote attacker can exploit this, via specially crafted web content, to cause a denial of service condition or the execution of arbitrary code. (CVE-2017-7005) Note that only 4th generation models are affected by these vulnerabilities."); script_set_attribute(attribute:"see_also", value:"https://support.apple.com/en-us/HT207801"); script_set_attribute(attribute:"solution", value: "Upgrade to Apple TV version 10.2.1 or later. Note that this update is only available for 4th generation models."); script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:N/C:C/I:C/A:C"); script_set_cvss_temporal_vector("CVSS2#E:POC/RL:OF/RC:C"); script_set_cvss3_base_vector("CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H"); script_set_cvss3_temporal_vector("CVSS:3.0/E:P/RL:O/RC:C"); script_set_attribute(attribute:"cvss_score_source", value:"CVE-2017-6989"); script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available"); script_set_attribute(attribute:"exploit_available", value:"true"); script_set_attribute(attribute:"vuln_publication_date", value:"2017/05/15"); script_set_attribute(attribute:"patch_publication_date", value:"2017/05/15"); script_set_attribute(attribute:"plugin_publication_date", value:"2017/05/17"); script_set_attribute(attribute:"plugin_type", value:"remote"); script_set_attribute(attribute:"cpe", value:"cpe:/a:apple:apple_tv"); script_end_attributes(); script_category(ACT_GATHER_INFO); script_family(english:"Misc."); script_copyright(english:"This script is Copyright (C) 2017-2019 and is owned by Tenable, Inc. or an Affiliate thereof."); script_dependencies("appletv_version.nasl"); script_require_keys("AppleTV/Version", "AppleTV/Model", "AppleTV/URL", "AppleTV/Port"); script_require_ports("Services/www", 7000); exit(0); } include("audit.inc"); include("appletv_func.inc"); url = get_kb_item('AppleTV/URL'); if (empty_or_null(url)) exit(0, 'Cannot determine Apple TV URL.'); port = get_kb_item('AppleTV/Port'); if (empty_or_null(port)) exit(0, 'Cannot determine Apple TV port.'); build = get_kb_item('AppleTV/Version'); if (empty_or_null(build)) audit(AUDIT_UNKNOWN_DEVICE_VER, 'Apple TV'); model = get_kb_item('AppleTV/Model'); if (empty_or_null(model)) exit(0, 'Cannot determine Apple TV model.'); fixed_build = "14W585a"; tvos_ver = '10.2.1'; # determine gen from the model gen = APPLETV_MODEL_GEN[model]; appletv_check_version( build : build, fix : fixed_build, affected_gen : 4, fix_tvos_ver : tvos_ver, model : model, gen : gen, port : port, url : url, severity : SECURITY_HOLE, xss : TRUE );NASL family Gentoo Local Security Checks NASL id GENTOO_GLSA-201706-15.NASL description The remote host is affected by the vulnerability described in GLSA-201706-15 (WebKitGTK+: Multiple vulnerabilities) Multiple vulnerabilities have been discovered in WebKitGTK+. Please review the CVE identifiers referenced below for details. Impact : A remote attack can use multiple vectors to execute arbitrary code or cause a denial of service condition. Workaround : There is no known workaround at this time. last seen 2020-06-01 modified 2020-06-02 plugin id 100675 published 2017-06-08 reporter This script is Copyright (C) 2017-2019 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/100675 title GLSA-201706-15 : WebKitGTK+: Multiple vulnerabilities code # # (C) Tenable Network Security, Inc. # # The descriptive text and package checks in this plugin were # extracted from Gentoo Linux Security Advisory GLSA 201706-15. # # The advisory text is Copyright (C) 2001-2017 Gentoo Foundation, Inc. # and licensed under the Creative Commons - Attribution / Share Alike # license. See http://creativecommons.org/licenses/by-sa/3.0/ # include("compat.inc"); if (description) { script_id(100675); script_version("3.2"); script_cvs_date("Date: 2019/04/10 16:10:17"); script_cve_id("CVE-2015-2330", "CVE-2015-7096", "CVE-2015-7098", "CVE-2016-1723", "CVE-2016-1724", "CVE-2016-1725", "CVE-2016-1726", "CVE-2016-1727", "CVE-2016-1728", "CVE-2016-4692", "CVE-2016-4743", "CVE-2016-7586", "CVE-2016-7587", "CVE-2016-7589", "CVE-2016-7592", "CVE-2016-7598", "CVE-2016-7599", "CVE-2016-7610", "CVE-2016-7611", "CVE-2016-7623", "CVE-2016-7632", "CVE-2016-7635", "CVE-2016-7639", "CVE-2016-7640", "CVE-2016-7641", "CVE-2016-7642", "CVE-2016-7645", "CVE-2016-7646", "CVE-2016-7648", "CVE-2016-7649", "CVE-2016-7652", "CVE-2016-7654", "CVE-2016-7656", "CVE-2016-9642", "CVE-2016-9643", "CVE-2017-2350", "CVE-2017-2354", "CVE-2017-2355", "CVE-2017-2356", "CVE-2017-2362", "CVE-2017-2363", "CVE-2017-2364", "CVE-2017-2365", "CVE-2017-2366", "CVE-2017-2367", "CVE-2017-2369", "CVE-2017-2371", "CVE-2017-2373", "CVE-2017-2376", "CVE-2017-2377", "CVE-2017-2386", "CVE-2017-2392", "CVE-2017-2394", "CVE-2017-2395", "CVE-2017-2396", "CVE-2017-2405", "CVE-2017-2415", "CVE-2017-2419", "CVE-2017-2433", "CVE-2017-2442", "CVE-2017-2445", "CVE-2017-2446", "CVE-2017-2447", "CVE-2017-2454", "CVE-2017-2455", "CVE-2017-2457", "CVE-2017-2459", "CVE-2017-2460", "CVE-2017-2464", "CVE-2017-2465", "CVE-2017-2466", "CVE-2017-2468", "CVE-2017-2469", "CVE-2017-2470", "CVE-2017-2471", "CVE-2017-2475", "CVE-2017-2476", "CVE-2017-2481", "CVE-2017-2496", "CVE-2017-2504", "CVE-2017-2505", "CVE-2017-2506", "CVE-2017-2508", "CVE-2017-2510", "CVE-2017-2514", "CVE-2017-2515", "CVE-2017-2521", "CVE-2017-2525", "CVE-2017-2526", "CVE-2017-2528", "CVE-2017-2530", "CVE-2017-2531", "CVE-2017-2536", "CVE-2017-2539", "CVE-2017-2544", "CVE-2017-2547", "CVE-2017-2549", "CVE-2017-6980", "CVE-2017-6984"); script_xref(name:"GLSA", value:"201706-15"); script_name(english:"GLSA-201706-15 : WebKitGTK+: Multiple vulnerabilities"); script_summary(english:"Checks for updated package(s) in /var/db/pkg"); script_set_attribute( attribute:"synopsis", value: "The remote Gentoo host is missing one or more security-related patches." ); script_set_attribute( attribute:"description", value: "The remote host is affected by the vulnerability described in GLSA-201706-15 (WebKitGTK+: Multiple vulnerabilities) Multiple vulnerabilities have been discovered in WebKitGTK+. Please review the CVE identifiers referenced below for details. Impact : A remote attack can use multiple vectors to execute arbitrary code or cause a denial of service condition. Workaround : There is no known workaround at this time." ); script_set_attribute( attribute:"see_also", value:"https://security.gentoo.org/glsa/201706-15" ); script_set_attribute( attribute:"solution", value: "All WebKitGTK+ users should upgrade to the latest version: # emerge --sync # emerge --ask --oneshot --verbose '>=net-libs/webkit-gtk-2.16.3:4'" ); script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:N/C:C/I:C/A:C"); script_set_cvss_temporal_vector("CVSS2#E:POC/RL:OF/RC:C"); script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H"); script_set_cvss3_temporal_vector("CVSS:3.0/E:P/RL:O/RC:C"); script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available"); script_set_attribute(attribute:"exploit_available", value:"true"); script_set_attribute(attribute:"plugin_type", value:"local"); script_set_attribute(attribute:"cpe", value:"p-cpe:/a:gentoo:linux:webkit-gtk"); script_set_attribute(attribute:"cpe", value:"cpe:/o:gentoo:linux"); script_set_attribute(attribute:"patch_publication_date", value:"2017/06/07"); script_set_attribute(attribute:"plugin_publication_date", value:"2017/06/08"); script_end_attributes(); script_category(ACT_GATHER_INFO); script_copyright(english:"This script is Copyright (C) 2017-2019 and is owned by Tenable, Inc. or an Affiliate thereof."); script_family(english:"Gentoo Local Security Checks"); script_dependencies("ssh_get_info.nasl"); script_require_keys("Host/local_checks_enabled", "Host/Gentoo/release", "Host/Gentoo/qpkg-list"); exit(0); } include("audit.inc"); include("global_settings.inc"); include("qpkg.inc"); if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED); if (!get_kb_item("Host/Gentoo/release")) audit(AUDIT_OS_NOT, "Gentoo"); if (!get_kb_item("Host/Gentoo/qpkg-list")) audit(AUDIT_PACKAGE_LIST_MISSING); flag = 0; if (qpkg_check(package:"net-libs/webkit-gtk", unaffected:make_list("ge 2.16.3"), vulnerable:make_list("lt 2.16.3"))) flag++; if (flag) { if (report_verbosity > 0) security_hole(port:0, extra:qpkg_report_get()); else security_hole(0); exit(0); } else { tested = qpkg_tests_get(); if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested); else audit(AUDIT_PACKAGE_NOT_INSTALLED, "WebKitGTK+"); }
Seebug
| bulletinFamily | exploit |
| description | This article is about [CVE-2017-2536](https://support.apple.com/en-us/HT207804) / [ZDI-17-358](http://www.zerodayinitiative.com/advisories/ZDI-17-358/), a classic integer overflow while computing an allocation size, leading to a heap-based buffer overflow. It was introduced in [99ed479](https://github.com/WebKit/webkit/commit/99ed47942b1dcf935accb23b355bc8a2e93650c9), which improved the way JavaScriptCore handled ECMAScript 6 spreading operations, and discovered by saelo in February. The PoC is short enough to fit into a tweet, and we have a fully working exploit for Safari 10.1, so this is going to be fun! ### The Bug The following code is used when constructing an array through [spread operations](https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Operators/Spread_operator): ``` SLOW_PATH_DECL(slow_path_new_array_with_spread) { BEGIN(); int numItems = pc[3].u.operand; ASSERT(numItems >= 0); const BitVector& bitVector = exec->codeBlock()->unlinkedCodeBlock()->bitVector(pc[4].u.unsignedValue); JSValue* values = bitwise_cast<JSValue*>(&OP(2)); // [[ 1 ]] unsigned arraySize = 0; for (int i = 0; i < numItems; i++) { if (bitVector.get(i)) { JSValue value = values[-i]; JSFixedArray* array = jsCast<JSFixedArray*>(value); arraySize += array->size(); } else arraySize += 1; } JSGlobalObject* globalObject = exec->lexicalGlobalObject(); Structure* structure = globalObject->arrayStructureForIndexingTypeDuringAllocation(ArrayWithContiguous); JSArray* result = JSArray::tryCreateForInitializationPrivate(vm, structure, arraySize); CHECK_EXCEPTION(); // [[ 2 ]] unsigned index = 0; for (int i = 0; i < numItems; i++) { JSValue value = values[-i]; if (bitVector.get(i)) { // We are spreading. JSFixedArray* array = jsCast<JSFixedArray*>(value); for (unsigned i = 0; i < array->size(); i++) { RELEASE_ASSERT(array->get(i)); result->initializeIndex(vm, index, array->get(i)); ++index; } } else { // We are not spreading. result->initializeIndex(vm, index, value); ++index; } } RETURN(result); } ``` At [[ 1 ]], the function computes the size of the output array, which it allocates and initializes at [[ 2 ]]. However, the size computation can overflow, causing a smaller array to be allocated. JSObject::initializeIndex does not perform any bounds checks as can be seen in the following piece of code: ``` /* ... */ case ALL_CONTIGUOUS_INDEXING_TYPES: { ASSERT(i < butterfly->publicLength()); ASSERT(i < butterfly->vectorLength()); butterfly->contiguous()[i].set(vm, this, v); break; } /* ... */ ``` As such, a heap buffer overflow occurs. The bug can be triggered through the following script: ``` var a = new Array(0x7fffffff); var x = [13, 37, ...a, ...a]; ``` A JSArray of size 0 is allocated, and then 232 elements get copied into it, which the browser does not like very much. The [patch](https://github.com/WebKit/webkit/commit/61dbb71d92f6a9e5a72c5f784eb5ed11495b3ff7) for this bug simply adds integer overflow checks to all affected tiers (interpreter + JITs). ### Exploitation Even though the PoC code given above uses a single array multiple times, JavaScriptCore will allocate a JSFixedArray for every spread operand of the array literal (in slow_path_spread). As such, roughly 4 billion JSValues will have to be allocated, taking up 32 GiB in RAM. Luckily, this isn’t much of a problem [due to the page compression performed by the macOS kernel](https://arstechnica.com/apple/2013/10/os-x-10-9/17/). It will, however, take roughly a minute to trigger the bug. What is left to do now is to perform some heap feng-shui to place something interesting on the heap that we will then overflow into. We use the following heap spray to exploit the bug: 1. Allocate 100 JSArrays of size 0x40000 and root them (i.e. keep references). This will trigger GC multiple times and fill up holes in the heap. 2. Allocate 100 JSArrays of size 0x40000, where only every second one is rooted. This triggers GC and leaves holes of size 0x40000 in the heap. 3. Allocate a larger JSArray and an ArrayBuffer of the same size. These end up directly after the spray from step 2. 4. Allocate 4 GiB of padding using JSArrays. 5. Trigger the bug by concatenating JSArrays with a combined size of 232 + 0x40000 (containing the repeated byte 0x41). The target buffer will be allocated in the sprayed region from step 2 and the victim buffers from step 3 will be overwritten. This increases the size of the victim array to the sprayed value (0x4141414141414141), so that it overlaps with the victim ArrayBuffer. The final steps immediately yield the fakeobj and addrof primitives described in section 1.2 of the [JavaScriptCore phrack paper](http://phrack.com/papers/attacking_javascript_engines.html) which can then be used to write code to a JIT page and jump to it. In our exploit we perform step 5 in a separate [web worker](https://developer.mozilla.org/en-US/docs/Web/API/Web_Workers_API/Using_web_workers), so that we can launch a second stage shellcode immediately after the victim arrays are overwritten. This way we do not need to wait for the full overwrite to finish, and the heap is only left in a broken state for a very short time, so that garbage collection does not crash (which runs concurrently starting from Safari version 10.1). The full exploit can be found on our [GitHub](https://github.com/phoenhex/files/blob/master/exploits/spread-overflow). |
| id | SSV:93177 |
| last seen | 2017-11-19 |
| modified | 2017-06-05 |
| published | 2017-06-05 |
| reporter | Root |
| title | Exploiting an integer overflow with array spreading (WebKit) |
References
- http://www.securityfocus.com/bid/98473
- http://www.securityfocus.com/bid/98473
- http://www.securitytracker.com/id/1038487
- http://www.securitytracker.com/id/1038487
- https://security.gentoo.org/glsa/201706-15
- https://security.gentoo.org/glsa/201706-15
- https://support.apple.com/HT207798
- https://support.apple.com/HT207798
- https://support.apple.com/HT207801
- https://support.apple.com/HT207801
- https://support.apple.com/HT207804
- https://support.apple.com/HT207804
- https://www.exploit-db.com/exploits/42125/
- https://www.exploit-db.com/exploits/42125/